电力系统分析综合程序(Power System Analysis Synthesis Program,PSASP)对变电站母线拓扑结构做了简化,潮流计算中不能反映变电站内部各引流线及CT潮流变化。通过分析PSASP程序和3/2接线方式的特点,提出了增加母线节点法和断面定义法...电力系统分析综合程序(Power System Analysis Synthesis Program,PSASP)对变电站母线拓扑结构做了简化,潮流计算中不能反映变电站内部各引流线及CT潮流变化。通过分析PSASP程序和3/2接线方式的特点,提出了增加母线节点法和断面定义法两种解决方案,并通过实际案例进行了验证。应用结果表明:两种方案均能够有效解决3/2接线中CT过载无法观测的问题。展开更多
设G=(V,E)是一个连通图,边集S(?)E是一个3-限制性边割,如果G-S是不连通的并且G-S的每个分支至少有三个点.图G的3-限制性边连通度λ_3(G)是G中最小的一个3-限制性边割的基数.图G是λ_3(G)连通的,如果3-限制性边割存在.G是λ_3-最优的,如...设G=(V,E)是一个连通图,边集S(?)E是一个3-限制性边割,如果G-S是不连通的并且G-S的每个分支至少有三个点.图G的3-限制性边连通度λ_3(G)是G中最小的一个3-限制性边割的基数.图G是λ_3(G)连通的,如果3-限制性边割存在.G是λ_3-最优的,如果λ_3(G)=ξ_3(G),其中ξ_3(G)=min{|[U,(?)]|:U(?)V,|U|=3 and G[U]是连通的).G[U]表示V的子集U的导出子图,(?)=V\U表示U的补.[U,(?)]是一条边的一个端点在U中另一个端点在(?)中的边的集合.本文给出了不含三角形的图是λ_3-最优的一些充分条件.展开更多
For two integers l ：〉 0 and k ≥ 0, define C（l, k） to be the family of 2-edge connected graphs such that a graph G ∈ C（l, k） if and only if for every bond S lohtain in E（G） with ｜S｜ ≤3, each component of G...For two integers l ：〉 0 and k ≥ 0, define C（l, k） to be the family of 2-edge connected graphs such that a graph G ∈ C（l, k） if and only if for every bond S lohtain in E（G） with ｜S｜ ≤3, each component of G - S has order at least （｜V（G）｜ - k）/l. In this note we prove that if a 3- edge-connected simple graph G is in C（10, 3）, then G is supereulerian if and only if G cannot be contracted to the Petersen graph. Our result extends an earlier result in [Supereulerian graphs and Petersen graph. JCMCC 1991, 9： 79-89] by Chen.展开更多
It is shown that the lower bound on the maximum genus of a 3-edge connected loopless graph is at least one-third of its cycle rank. Moreover, this lower bound is tight. There are infinitely such graphs attaining the b...It is shown that the lower bound on the maximum genus of a 3-edge connected loopless graph is at least one-third of its cycle rank. Moreover, this lower bound is tight. There are infinitely such graphs attaining the bound.展开更多
文摘电力系统分析综合程序(Power System Analysis Synthesis Program,PSASP)对变电站母线拓扑结构做了简化,潮流计算中不能反映变电站内部各引流线及CT潮流变化。通过分析PSASP程序和3/2接线方式的特点,提出了增加母线节点法和断面定义法两种解决方案,并通过实际案例进行了验证。应用结果表明:两种方案均能够有效解决3/2接线中CT过载无法观测的问题。
基金supported by NSFC (No.10671165)XJEDU (No.2004G05).
文摘设G=(V,E)是一个连通图,边集S(?)E是一个3-限制性边割,如果G-S是不连通的并且G-S的每个分支至少有三个点.图G的3-限制性边连通度λ_3(G)是G中最小的一个3-限制性边割的基数.图G是λ_3(G)连通的,如果3-限制性边割存在.G是λ_3-最优的,如果λ_3(G)=ξ_3(G),其中ξ_3(G)=min{|[U,(?)]|:U(?)V,|U|=3 and G[U]是连通的).G[U]表示V的子集U的导出子图,(?)=V\U表示U的补.[U,(?)]是一条边的一个端点在U中另一个端点在(?)中的边的集合.本文给出了不含三角形的图是λ_3-最优的一些充分条件.
基金Supported by the Science Foundation of Chongqing Education Committee (Grant NoKJ100725)
文摘For two integers l ：〉 0 and k ≥ 0, define C（l, k） to be the family of 2-edge connected graphs such that a graph G ∈ C（l, k） if and only if for every bond S lohtain in E（G） with ｜S｜ ≤3, each component of G - S has order at least （｜V（G）｜ - k）/l. In this note we prove that if a 3- edge-connected simple graph G is in C（10, 3）, then G is supereulerian if and only if G cannot be contracted to the Petersen graph. Our result extends an earlier result in [Supereulerian graphs and Petersen graph. JCMCC 1991, 9： 79-89] by Chen.
文摘It is shown that the lower bound on the maximum genus of a 3-edge connected loopless graph is at least one-third of its cycle rank. Moreover, this lower bound is tight. There are infinitely such graphs attaining the bound.
